The purpose of this project is to define the biosynthetic sequence of collagen cross-linking catalyzed by lysyl oxidase, to investigate the cross-link products produced in vitro and to determine whether the products synthesized in the in vitro model system consisting of highly purified collagen fibrils and lysyl oxidase are similar to those found in vivo. BIBLIOGRAPHIC REFERENCES: Siegel, R.C.: Collagen cross-linking: The effect of D-Penicillamine on cross-linking in vitro. J. Biol. Chem. 252:254-259, 1977. Fessler, J.H., Doege, K.J., Siegel, R.C., and Fessler, L.I.: Procollagen association into supramolecular structures. Fed. Proc. 36:680, 1977.